The water content of pulp sludge (pulp sludge means sludge wasted from a pulp beating process) is more than 80% by weight, which generally made if impossible to incinerate pulp sludge using fuel oil.
Therefore, in the past pulp sludge could only be incinerated after being dried or could be utilized for reclamation to dispose of it.
However, such means were remarkably troublesome because incinerating with fuel oil or conveying for reclamation cost too much and there was the possibility that poisonous gas which was exhausted by incinerating might destroy the environment.
On the other hand, in Japan, much effort has been required to ensure adequate energy sources for the reason of being mainly dependent on imported natural energy sources.
To solve such problems as described above, there has been a long felt need for developing the means that is capable of profitably utilizing industrial waste for energy sources.